Tremadog Bay Subtidal Macrobenthic Study dataset https://portal.medin.org.uk/portal/start.php?tpc=007_NRW_DS109835 The Habitats Directive establishes that the management of Special Area of Conservation (SACs) should aim to achieve the 'Favourable Conservation Status' (FCS) of habitats and species as defined in the Directive. In the case of SACs, the features to which FCS applies are the habitats and/or species listed in Annex I and Annex II of the Habitat Directive for which the individual site has been selected. Infaunal monitoring work is required to provide management feedback and enable reporting on the FCS of infaunal aspects of SACs, Special Protection Areas (SPAs: Birds Directive) and Special Sites of Scientific Interest (SSSI). The aim of this data capture was to gather repeatable data to provide reference conditions and to support the identification of the two characteristics of the Pen Llyn a'r Sarnau large shallow inlet and bays feature. Tremadog Bay a large shallow Inlet and Bay within the Pen Llyn a'r Sarnau SAC. Two important characteristics of this feature have been identified. These are: 1. The variety of subtidal sediment communities within the large shallow inlet and bay 2. The species richness and diversity of the sublittoral mixed sediment south west of Pwllheli 20080430